A beleagured rail operator majority-owned by a North East transport giant has been warned it won’t be able to bid for future franchises unless its performance improves.

Govia Thameslink Railway – a joint venture between Newcastle-headquartered Go-Ahead Group and Keolis – operates the troubled Southern franchise which has been beset by a catalogue of cancellations and delays.

The firm claims issues affecting service for the London and the South East, which is ranked the country’s worst for customer satisfaction, have been caused by staff shortages and industrial action, while unions have blamed poor management.

The issues which have triggered a month-long emergency timetable axing 341 trains a day, which sparked protests by commuters.

Now rail minister Claire Perry has warned Govia Thameslink Railway (GTR) it will not be able to bid for future franchises unless it improves its performance.

Ms Perry, who has been rail minister for two years, said: “It’s been quite clear to me companies who cannot deliver a good service, particularly over the things they can control, should not be bidding for new franchises and we need to be clear about that.

Ms Perry said “only 15%” of the original timetable’s services had been cancelled and 65% of the failures were down to problems with the track. She added: “By April of this year, things were okay.

“In April we had a reliability rate of about 84%. Not good enough, I would be the first to say that.

“Since that we have seen both planned and unplanned industrial action which has meant there is no certainty about the services and it’s just been absolutely dreadful.”

A spokesman for GTR said: “We understand the strength of feeling among passengers and their frustration at the poor service and increase in random cancellations since the dispute with the RMT began.

“That is why we are introducing the amended timetable to restore greater consistency in the short term so passengers can plan around it.

“We are very sorry for the effect on our passengers and we are determined to provide the level of service they rightly demand.

“We will continue to do everything we can to bring this unnecessary industrial action, which is affecting the service so badly, to a close.”

GTR took over the Southern franchise last year, and rail performance statistics show the service has declined steeply. Alex Prosser-Snelling, one of the organisers of the London protest said: “We aren’t people who protest normally but everyone’s fed up with the service.

“Southern mismanagement is needlessly wrecking passengers’ evenings, interfering with childcare and stressing out the workforce.

“Southern needs to get a grip – and if they can’t or won’t the Government shouldn’t let them run a railway.”

At present, Govia is shortlisted for the West Midlands franchise, a service it has operated since 2007 which expires in October 2017.

It runs the Southeastern and London Midland service as well as the Govia Thameslink Railway.

In March, Go-Ahead lost out to Arriva in its joint bid with Keolis to run the London Overground contract, and last December it also lost out to the same firm in its bid to take over the Northern Franchise, having submiited a joint bid with Keolis.

That same month Go-Ahead said it was disappointed not to have been awarded the TransPennine Express franchise, losing out to First Group.